In 1989, two Pioneer corn hybrids, 3377
and 3389, were grown under irrigation and
harvested at 80% milk line kernel maturity.
Voluntary intakes and ADF digestibilities were
similar for all hybrid, inoculant, and storage
time combinations; however, DM digestibility
was higher for 3377 silage than for 3389, and
DM, CP, and NDF digestibilities were higher
at the 50- than the 250-day storage time. The
inoculant did not influence either voluntary
intake or digestibility.
In 1990, the same corn hybrids and
DeKalb DK 42Y and Pioneer 8358 grain
sorghum hybrids were grown under both
irrigated and dryland conditions. Whole-plant
DM contents were similar for irrigated
hybrids, but dryland corns had lower DM
values than sorghums. Whole-plant DM
yields were higher for irrigated hybrids, and
irrigated corns had higher yields than irrigated
grain sorghums. Grain yields were higher for
dryland grain sorghums than for dryland
corns. Significant crop × growing condition
× storage time interactions occurred for
voluntary intake, DM, NDF, and ADF
digestibilities. At 50 days, voluntary intake
was higher for grain sorghums, and whole-plant
DM digestibilities were similar within
each crop, but grain sorghum silages had
lower digestibilities than corn silages. At 50
days, voluntary intake was similar for all
silages, and DM digestibility was higher for
irrigated corn silages than for dryland corn
silages and for all grain sorghum silages.
The agronomic performances of the
irrigated and dryland grain sorghums suggest
that they are equivalent to dryland corn silage.
Irrigated and dryland grain sorghum silages
were of similar nutritive quality to the corn
silages.
